The present disclosure relates to a sheet feeding device feeding a sheet, and an image reading device and an image forming apparatus including this sheet feeding device.
Conventionally, in a sheet feeding device (a sheet feeder) feeding a sheet, a one-way clutch attached to a sheet feeding roller to transmit power in one way is known. The power used for rotation is inputted from the one-way clutch to the sheet feeding roller, and then, the sheet feeding roller feeds the sheet.
The one-way clutch includes a drive inputting portion, a drive transmitting portion and a drive outputting portion. The drive transmitting portion is arranged between the drive inputting portion and drive outputting portion. The drive outputting portion corresponds to the sheet feeding roller. When a protrusion protruded toward the drive transmitting portion from the drive inputting portion is engaged with a notch formed in the drive transmitting portion, the power is transmitted from the drive inputting portion to the drive transmitting portion.
However, since the protrusion and notch respectively formed in the outer peripheral surfaces of the drive inputting portion and drive transmitting portion are engaged with each other, a length in an axial direction of a drive transmission mechanism transmitting the power to the sheet feeding roller is increased. As a result, in the sheet feeding device, there is a problem that a space occupied by a sheet feeding portion is increased.